The need to improve the bioavailability, pharmacology, cytotoxicities, and interval dosing of antiretroviral medications in the treatment of human immunodeficiency virus (HIV) infection is notable (Broder, S. (2010) Antivir. Res., 85:1-18; Este et al. (2010) Antivir. Res., 85:25-33; Moreno et al. (2010) J. Antimicrob. Chemother., 65:827-835). Since the introduction of antiretroviral therapy (ART), incidences of both mortality and co-morbidities associated with HIV-1 infection have decreased dramatically. However, many limitations associated with ART still remain which prevent full suppression of viral replication in HIV-infected individuals. These limitations include poor pharmacokinetics (PK) and biodistribution, life-long daily treatment, and multiple untoward toxic side effects (Garvie et al. (2009) J. Adolesc. Health 44:124-132; Hawkins, T. (2006) AIDS Patient Care STDs 20:6-18; Royal et al. (2009) AIDS Care 21:448-455). Since antiretroviral medications are quickly eliminated from the body and do not thoroughly penetrate all organs, dosing schedules tend to be complex and involve large amounts of drug. Patients have difficulty properly following therapy guidelines leading to suboptimal adherence and increased risk of developing viral resistance, which can result in treatment failure and accelerated progression of disease (Danel et al. (2009) J. Infect. Dis. 199:66-76). For HIV-infected patients who also experience psychiatric and mental disorders and/or drug abuse, proper adherence to therapy is even more difficult (Meade et al. (2009) AIDS Patient Care STDs 23:259-266; Baum et al. (2009) J. Acquir. Immune Defic. Syndr., 50:93-99). If dosing is not strictly maintained and consistent, virus can mutate and drug resistance will ultimately develop.
Accordingly, there is a need for drug delivery systems that optimize cell uptake and retention, improve intracellular stability, extend drug release, maintain antiretroviral efficacy, and minimize cellular toxicity within transporting cells.